The invention relates generally to the field of stringed musical instruments having frets, and particularly to stringed musical instruments that may be played using frets and without using frets. More particularly, the invention provides for frets on a fingerboard or neck of a stringed musical instrument that can be raised or lowered in unison, allowing a musician to play the instrument as fretted and unfretted.
Most stringed musical instruments, and particularly guitars and bass guitars, comprise a body fixed to a neck having a fingerboard, and a headstock having tuning pegs and tuning knobs connected to the neck opposite the body. Strings are fixed to the body at one end and adjustably connected to the tuning pegs at the other end for adjusting the string tension and corresponding string pitch. The strings are tensioned between a bridge positioned on the body and a nut positioned on the far end of the neck. A musician plays the instrument by strumming or plucking the strings with one hand while selecting a pitch by pressing the strings down against the fingerboard at suitably selected positions with the other hand. The fingerboard may have frets below the strings and positionally fixed along the fingerboard, oriented substantially perpendicular to the direction of the strings. The fingerboard may be also be unfretted.
For instruments with frets, a musician presses the strings against the fingerboard behind selected frets opposite the body, to produce a pitch from each string that is precisely determined by the distance between the fret and the bridge, and the characteristics of the particular string. The sounds from a fretted instrument tend to be sharp and clearly defined. For instruments without frets a performer presses the strings against the fingerboard to produce a pitch that is determined by the distance between the point where the string is pressed against the fingerboard and the bridge, as well as the characteristics of the particular string. Unfretted instruments usually produce a softer sound and provide a wider range of selectable pitches available to a musician due to the wider range of points where a string may be pressed against a fingerboard. They also enable a musician to produce certain sound characteristics that cannot be produced with an equivalent fretted instrument.
Because of the different sounds produced by fretted and unfretted instruments, musicians sometimes rely on two different instruments, a fretted and an unfretted instrument. It is desirable to have a single instrument that is capable of both fretted and unfretted play, which may be quickly and easily switched between the two modes of play.